package config

import (
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
)

// Config holds forge-mesh server configuration loaded from config.json.
type Config struct {
	ListenAddr        string         `json:"listen_addr"`
	DataDir           string         `json:"data_dir"`
	DatabasePath      string         `json:"database_path"`
	OperatorClearance int            `json:"operator_clearance"`
	Auth              AuthConfig     `json:"auth"`
	WalletPolicy      WalletPolicy   `json:"wallet_policy"`
	Stratum           StratumConfig  `json:"stratum"`
	Forge             ForgeConfig    `json:"forge"`
	Court             CourtConfig    `json:"court"`
	Telegram          TelegramConfig `json:"telegram"`
}

// TelegramConfig holds alert bot settings (W19).
type TelegramConfig struct {
	Enabled  bool   `json:"enabled"`
	BotToken string `json:"bot_token"`
	ChatID   string `json:"chat_id"`
}

type AuthConfig struct {
	BasicUsername string `json:"basic_username"`
	BasicPassword string `json:"basic_password"`
	FleetSecret   string `json:"fleet_secret"`
}

type WalletPolicy struct {
	DefaultWallet string `json:"default_wallet"`
	Currency      string `json:"currency"`
}

type StratumConfig struct {
	XMRListen   string `json:"xmr_listen"`
	RVNListen   string `json:"rvn_listen"`
	UpstreamXMR string `json:"upstream_xmr"`
	UpstreamRVN string `json:"upstream_rvn"`
}

type ForgeConfig struct {
	SigningKeyPath string `json:"signing_key_path"`
	ArtifactsDir   string `json:"artifacts_dir"`
}

type CourtConfig struct {
	OllamaURL string `json:"ollama_url"`
	Enabled   bool   `json:"enabled"`
}

// Load reads and parses config from the given JSON file path.
func Load(path string) (*Config, error) {
	data, err := os.ReadFile(path)
	if err != nil {
		return nil, fmt.Errorf("read config: %w", err)
	}

	var cfg Config
	if err := json.Unmarshal(data, &cfg); err != nil {
		return nil, fmt.Errorf("parse config: %w", err)
	}

	cfg.applyDefaults(path)
	if err := cfg.validate(); err != nil {
		return nil, err
	}

	return &cfg, nil
}

func (c *Config) applyDefaults(configPath string) {
	if c.ListenAddr == "" {
		c.ListenAddr = ":8989"
	}
	if c.DataDir == "" {
		c.DataDir = filepath.Dir(configPath)
	}
	if c.DatabasePath == "" {
		c.DatabasePath = filepath.Join(c.DataDir, "forge-mesh.db")
	}
	if c.Auth.BasicUsername == "" {
		c.Auth.BasicUsername = "admin"
	}
	if c.Auth.BasicPassword == "" {
		c.Auth.BasicPassword = "changeme"
	}
	if c.WalletPolicy.Currency == "" {
		c.WalletPolicy.Currency = "XMR"
	}
	if c.Stratum.XMRListen == "" {
		c.Stratum.XMRListen = ":3333"
	}
	if c.Stratum.RVNListen == "" {
		c.Stratum.RVNListen = ":3388"
	}
	if c.Forge.ArtifactsDir == "" {
		c.Forge.ArtifactsDir = filepath.Join(c.DataDir, "artifacts")
	}
	if c.Forge.SigningKeyPath == "" {
		c.Forge.SigningKeyPath = filepath.Join(c.DataDir, "signing.key")
	}
	if c.Court.OllamaURL == "" {
		c.Court.OllamaURL = "http://127.0.0.1:11434"
	}
	if c.OperatorClearance == 0 {
		c.OperatorClearance = 4
	}
}

func (c *Config) validate() error {
	if c.ListenAddr == "" {
		return fmt.Errorf("listen_addr is required")
	}
	return nil
}

// EnsureDataDirs creates data directories referenced by the config.
func (c *Config) EnsureDataDirs() error {
	dirs := []string{c.DataDir, c.Forge.ArtifactsDir}
	for _, dir := range dirs {
		if err := os.MkdirAll(dir, 0o755); err != nil {
			return fmt.Errorf("mkdir %s: %w", dir, err)
		}
	}
	return nil
}